Electric-current transformer.



P. HILDEBRAND. ELECTRIC CURRENT TRANSFORMER.

APPLIUATION FILED FEBJO, 1913.

,5 Patented July 7, 19m

marrnn sTA'rns PATENT OFFICE.

PAUL I-IILIDEBRAND, OF MUNICH, GERMANY.

ELECTRIC- CURRENT TRANSFORMER.

Specification of Letters Patent.

Application filed February 10, 1913. Serial No. 747,218.

. oughly efiicient and reliable.

- In carrying my invention into practice, I

provide a transformer, preferably connected through a pair of condensers, with a pole changer, such as a pole changing switchand an alternating current electrom'agnet, the

latter being adapted to actuate the switch in a manner more fully hereinafter described, Direct current from a suitable source is vadmitted to'the device, the pole changing switch converting the direct current into :11- ternating current which passes to the con I densers, and a very small fractional part of the alternating current flowing from the condensers to the electromagnet which is v thus operated by current of the same voltage as the direct current. The pole changing switch is preferably carried by or on the armature of the electromagnet and therefore operates synchronously with the latter.

One embodiment of the invention is schematically illustrated in the accompanying drawing, whereinp designates generally a pole changing switch adapted to be actuated by an alternating current magnet WV. -M.; O and C are two condensers and T is a transformer. The switch P, above referred to, consists of two levers l0 and 11 insulated from each other on a rod or support 12 fixed in the armature A of the electromagnet W M. As

the armature oscillates from one pole to the other of the magnet, the levers 10 and 11 are also caused to oscillate.

The operation of my novel form of trans-' former'is as follows :A direct current of say 110.0r 220 volts is conducted over two pairs of suitable contacts, such as contact springs 1, 1 and 2, 2*, so that the diagonally opposed contacts, 6. g. l and .Zhave an opposite sign to that of the contacts 1 and 2. Between these pairs of contacts, the two contactlevers l0 and 11, insulated from each other, are caused by the magnet YV. M. to oscillate. The levers 10 and 11 arelsecured to the rod 12 by means of eyes 3 and 3, respectively. This oscillation of the levers 'causes quick changes of polarity and the consequent production of alternating currents of 110 volts, 220 volts, etc.' The condensers C and'C' are charged with the alternating current, an exceedingly small part of this current flowing to the electromagnet V M' to operate the same, and the balance of the vcurrent flowing through the transformer T by which the voltage is reduced to 6, 8, 10 volts etc, as desired. It has been found, in practice, that the amount'of cur- .rent flowing from the condensers C and C to the electromagnet W M and suflicient to operate the latter, is so slight as to be practically incapable of measurement-r Having described my invention, what I claim is 1. A current converter, embodying therein a current transformer, contact members electrically'connected to a source of direct electric current, a pole changer electrically connected to said transformer and operatively related to said contacts, ,said pole changer adapted to convert direct current' nto alternating current before said current Patented July '7, 1914.

reaches the primary winding of said trans former, and an electromagnetic device energized by a part of said alternating current and adapted to actuate said pole changer.

2. A current converter, embodying therein a circuit including a current transformer and a pole changer, contact members electrically connected to a source of direct electric current, and an .electromagnetic device included in said first named circuit and 1; adapted to actuate said pole changer to c0n-' vert the direct current passing from said contact members to said transformer into alternating current. Y

I 3. A current converter, embodying therein a circuit including a current transformer, a pole changer, and condenser members, contact members. electrically connected to a source of direct electric current and in operative relation to said pole changer, and an In testimony whereof I have aflixed my electromagnet connected to said cfondensfir signature in presence of two witnesses. members and adapted to receive rom t e latter alternating current at the same vOlt- PAUL HILDEBRAND' 5 age as said direct current, said electromag- Witnesses:

net being adapted to actuate said pole RICHARD LEMP, changer. JOHANNA STERN. 

